'IMPROVED GRIFFITH CLUB MICROSCOPE'

MAKER: BAUSCH & LOMB

INVENTER: EZRA H. GRIFFITH

c. 1887

Serial Number: 933

INTRODUCTION:This microscope is one of the most unique 19th century microscope stands invented by an American. Its unusual features that set it apart from most microscopes of that era, are its foot, which is in an unusual configuration to double as a slide turntable, and its unusual form of fine focus which acts on the coarse focus control. Ringing tables were used to facilitate placing a 'ring' of sealing compound around a circular coverslip to protect and seal the specimen and mountant from the atmosphere. Ringed slides generally are better preserved over time. Although many ringing tables were produced, Griffith was the first to incorporate the device as a removeable part of the microscope stand itself.

Because my example has a damaged case, this page combines images of two different Griffith Club microscopes. In addition, another example is shown in the center at the bottom of the page (serial number 922), with a lamp, from another private collection, while the image of a preserved case, shown to the left, is from another example (case serial number 870, instrument serial 880); other images are from my own example, serial number 933, obtained in 2017 from Dr. Manuel del Cerro.
Although mine did not come with the parts to hold the lamp on its upright, I made these parts to match the rest of the lamp-holding parts and used other examples as models.
I am grateful to the owner, and former owner, of the other two instruments shown here for allowing me to share their images with you.

DESCRIPTION:

These microscopes are signed on the unusual turntable/foot 'E.H.GRIFFITH, FAIRPORT, N.Y., PAT. DEC 14 86, xxx'(xxx representing the serial number, in the case of mine, 933). The serial number is also found on the rear edge of the inside of the case.

The foot also serves as a slide-ringing turntable which can be detached from the rest of the instrument, turned upside down and, placed on the upright inside the case where it can be turned and spins easily on a point. The turntable has pins which are self centering(see more details below). The foot also has three pairs of holes to receive a 3-part articulated support for an oil lamp. In the case of mine and most other examples, only two parts are present in the case. The shallow cup actually supporting the lamp is a realistic replica which I produced and plated to match the original. In most illustrations, the lamp supplied with the microscope had no reflector, but at least one example does, and I do show mine with a reflector as well as without it.

The plano and concave mirror swings on an axis which is even with the stage after Zentmayer's design; the ring it rotates from is silvered, calibrated in 5 degree increments, from 0 to 90 degrees, with each ten degree increment numbered. It can be swung above the stage for top-lighting of opaque objects. The mirror is gimbaled and the mirror support slides up and down in a slot in the front of its tail piece, in a manner very similar to many Bausch & Lomb models of the same era.

There is a straight rack and pinion coarse focus. For fine focus a worm screw acts on a sleeve or tube that surrounds the inner axle. This mechanism is explained in greater detail below.

A pair of stage clips are on a single axle attached to the front of the limb. The center of the stage clip axle has a square profile and the springy plate which holds it in place then allows the clips to remain up or down as desired. The stage is topped with black glass. There is a simple substage sleeve attached to the bottom of the stage. A wheel of apertures fits into the substage sleeve. While the main support for the wheel of apertures is lacquered brass, the aperture wheel itself is made of hard rubber, another feature found most often on Bausch & Lomb instruments. A tiny screw from the brass part projects down into one of four tiny depressions on the upper surface of the aperture disk, thereby centering each aperture over the optical axis as the disk is rotated.

Two objectives are present, each in its own can. The 2/3 inch is housed in a can signed "2/3, E.H.Griffith" and is signed on the objective 'E.H.Griffith, Fairport, N.Y.' It is also signed '36o' and also a part number '129.' The 1/5 inch can is signed '1/5, E.H. Griffith' and the objective is signed: '1/5, E.H. Griffith Fairport, N.Y.' and is also signed '115o. A single unmarked eyepiece is present.

THE FINE FOCUS:

The images to the left serve to illustrate how the fine focus mechanism works. The first image shows the axle controlling the coarse focus with all of the parts on the right side removed. This axle carries the coarse focus pinion inside the pinion box. The knob on the left side acts on this axle alone.

The second image on the left shows the right coarse focus knob in place without any of the fine focus parts. Note the hollowed-out inner surface of the right coarse focus knob.

The third image down shows the outer sleeve, found only on the right side; the right side of this sleeve expands into a fine focus wheel that rides inside the hollowed-out coarse focus knob on the right side of the instrument. It is important to understand that this wheel and the outer sleeve are made of a single piece of brass. The worm gear machined into this outer sleeve is the one acted on by the fine focus worm screw.

Shown next is a thin leather 'washer' or clutch-pad. The center of this clutch-pad or washer sits over the fine focus wheel fitting inside the coarse focus knob. The pressure on the center of the leather clutch pad is adjusted so that the right coarse focus knob can rotate around the fine focus wheel as it remains stationary, yet applies enough pressure on the fine focus wheel so that when the fine focus worm screw is turned, the coarse focus knob is moved very slowly.

A nickeled washer, which is slightly convex towards the knobs, fits over the leather clutch pad and is held in place on one side by two screws fitting into the coarse focus knob.

As shown in the image to the left, a small brass adjustment knob provides the adjustment to the nickeled washer, which because it is slightly convex, applies pressure mainly to the central part of the leather washer fitting over the wheel of the fine focus sleeve. Adjusting this tension to the proper amount allows the coarse focus knob to rotate as the fine focus sleeve remains stationary,(held that way by the worm screw), yet imparts enough friction against the coarse focus knob when the worm screw is turned to result in very slow motion. This is an improvement over Griffith's earlier form of worm screw fine focus, which could not be left engaged when the coarse focus was being used. It works suprisingly well when properly adjusted and properly lubricated.

A blackened spring holds the fine adjustment worm screw against its worm gear on the outer sleeve. Tension of the wormscrew against the outer sleeve worm gear can be adjusted by a small knurled brass knob projecting backwards. One of the points made by Griffith about the advantage of his fine focus is that it could be used through the entire range of focus.

THE TURNTABLE:

The interior of the case has a spindle support for the turntable. The foot and the lower half of the pillar can be unscrewed as a unit from the upper half of the pillar and placed on the spindle support in the case. The side and bottom of the foot (the top of the turntable) are nickel plated. There are concentric rings etched in the center of the turntable.

On the nickeled surface of the turntable are five pins. As shown in the diagram to the right, pins A and B sit in a sprung ring (R) that rotates inside the table. With the turntable held stationary, the two pins are rotated counterclockwise against the spring, the slide is then placed between them, and the spring slowly released. A and B then firmly grip the slide and at the same time automatically center it, also registering it against the fixed pin D. The pin labeled E is to register the end of the slide. C is a pin rotating on a small disk; this pin can be fixed in a position to offset the centering of the slide; this can allow the user to ring multiple smaller specimens, offset from the center of the slide.

HISTORY OF THE GRIFFITH CLUB MICROSCOPE

Ezra Horace Griffith, who was a soda company representative, initially of Fairport and later of Rochester, New York, founded a side business in Fairport about 1875 providing microscopical 'supplies.' He first reported the Griffith Club Microscope at the meeting of the American Society of Microscopists in August of 1879, but it was not published until the 1880 Proceedings1. It was also reported in 1881 in both the American Monthly Microscopical Journal2 and the JRMS3. One may conclude therefore that his first version of the Griffith Club microscope was invented sometime between 1875 and 1879.

Griffith contributed to both American and British Microscope journals. His many contributions included not only reports about the Club Microscope in its several iterations, but also various microscope accessories applicable to microscopes in general. He was also an important figure in American Microscopy, being instrumental in forming several microscopical clubs and also the American Microscopical Society.

Griffith's first version of the Club microscope included a tripod foot which could be used as a turntable, but it differed from the later versions. This microscope had coarse focus by sliding the tube, and fine focus of the stage via a large knob with a spiral groove moving a pin fixed to a rod which moved the stage. This early version, examples of which are in the Billings Collection and the RMS collection4 had three small projections for support of foot/turntable:

Although in the engravings these feet are solid and decorated, in the two examples I mentioned the feet are simply bent wire. The mirror of this original form, provides a wide range of positions, both closer to the stage and also being able to rotate to extremely oblique positions or even to above the stage. This feature, in slightly modified form, would continue in all the other models. The turntable on this model could be used installed on a part of tube support for the microscope as shown in figure No. 2. It could also serve as a foot for the microscope, as shown in figure No. 1. Another way of mounting the microscope was on an included second pillar with a sharp wood screw on one end, allowing the microscope to be mounted onto a table or even a tree (fig no. 3).

In the 1881 volume of the American Society of Microscopists, as well as the JRMS of that year5, he reported constructional improvements in the focusing mechanism and the addition of a substage wheel of diaphragms.

Later in 1881, a rack and pinion coarse focus was added; in this model6, the fine focus, acted via a worm screw on a worm gear machined directly into the sleeve of the coarse focusing knob on the right. The worm screw could be engaged or disengaged into that worm gear. The mechanism to do this was a strong spring pressing against the wormscrew fine focus, and a brass cam (arrow in image to the right) of varying thickness controlled by a short handle protruding to the right of the microscope. When the widest part of the cam was engaged, the wormscrew was pushed back against the spring and not engaged to the worm gear on the coarse focusing knob sleeve. As the cam was turned away from that position, the wormscrew shaft then rested against the thinner part of the cam, allowing it to come closer and make contact with the worm gear on the coarse focusing knob sleeve. Because the coarse focus knob and sleeve on the right were made of a single piece of metal, when the fine focus worm screw was engaged, the coarse focus could not be used unless the fine focus was first disengaged using the cam control. Griffith termed this6 model the 'Improved Griffith Club Microscope.'

In 1883, Griffith was elected a Fellow of the RMS, and in that year's volume of the JRMS7 he illustrated the Improved Griffith Club Microscope again. A swinging substage similar to those of Bausch & Lomb was also provided. The fine adjustment on this model was still engaged or disengaged from the coarse via the same mechanism. It is stated therein that the microscope was manufactured by Bausch & Lomb, and it was offered in the 1884 B&L Catalog.

In 18888 he reported, in the Proceedings of the American Society of Microscopists, his constantly-engaged fine adjustment working on the coarse adjustment. This is the type of fine adjustment supplied with the microscope in my collection. This was also reported in the December 1889 issue of the American Monthly Microscopical Journal.9 As shown to the left, this model was offered in the 1889 Bausch & Lomb catalog and an option was the supplementary Gundlach-type foot.

During his association with Bausch & Lomb, Griffith sold microscopes through his own catalog, through retailers, and it was also listed in the Bausch & Lomb catalog.

In 1892 Griffith and Bausch & Lomb apparently dissolved their relationship; Griffith then went to Gundlach for manufacture in the USA and (apparently) to Field of Birmingham in the U.K. for manufacture there. The association of Griffith with Gundlach is not surprising, since Gundlach had also left Bausch & Lomb on an unhappy note.

Griffith's microscopes were offered with options for a supplementary Gundlach-type foot when sold by Bausch & Lomb, allowing the turntable to be used at the same time as the rest of the microscope.

Starting about 1890-92, Griffith added an Abbe substage condenser and a double nosepiece to his stand10. The straight rack and pinion was replaced by a diagonal rack and spiral pinion at that time was well.
An article published in the 1892 volume of the American Microscopical Journal, stated that the stand would, because of the increased sophistication, simply be called the 'Griffith Microscope.' The word 'Club' was to be deleted from that time on. It also reported (naturally) that it was supplied with Gundlach optics.

About 1893 Griffith moved to Chicago where that year he received an award for his microscope during the Columbian World Exposition. He died in Illinois of congestive heart failure on August 24, 1894, aged 56.

An example of the first version of the Griffith Club Microscope is number 71789 in the Billings collection (although not illustrated in their catalog). Another example is number 98, page 106 in: Turner, G. The Great Age of the Microscope... 1989. Adam Hilger, Bristol and New York.

An example of the final version of the Griffith Microscope is number 71790 in the Billings collection, and shown on page 90 of the catalog(figure 167). It is serial numbered 1069, and could have been made by Bausch & Lomb or Gundlach, but likely dates to about 1891 because this design was not produced until about 1891.